Drawing device



G. ELGER DRAWING DEVICE Dec. 6, 1966 Filed Nov. 10, 1964 F igA In ventor= cierd Elger Mb M United States Patent 3,289,2d9 Patented Dec. 6, 19%6 Flee DRAWING DEVIQE Gerd Elger, Wintertliur, Switzerland, assignor to Anne Elger, Nnrtingen (Neckar), Germany Filed Nov. 10, N64, Ser. No. 410,055 Claims priority, application Germany, Nov. 20, 1963,

7 Claims. (Cl. 33--27) This invention relates in general to drawing instrument construction, and in particular to a new and useful drawing instrument for drawing curved and straight lines and including a pricking tip or pin for anchoring the instrument and forming a center, and to novel means for holding and positioning said pricking tip.

The present invention deals with a drawing instrument which generally comprises a transparent element provided with a plurality of holes arranged at predetermined distances from a central hole, the holes being provided for the introduction of a stylus or pencil, and the instrument including scales correlated with the spacing between holes. It has also been known with such instruments to employ a pricking tip which may be used, for example, in conjunction with a central hole in order to establish a central point, for example, when drawing a curved line. Prior to the present invention it has been found to be difficult to associate such a pricking tip with the drawing instrument because of the difiiculty of connecting structural parts of different stability together and the difliculty in insuring that the articulation of the tip is sturdy and accurate. A further difiiculty is that the mounting means proposed heretofore made it difficult to handle the instrument safely because of the projecting pricking tip. A further disadvantage in the known devices is that the tip could not be easily maintained in a position in which it did not project from the instrument and thereafter be moved substantially in a parallel direction to pierce the underlying sheet to be inscribed. With prior art devices, the pin, when brought into an operative position, would describe an arc of a circle and soon would leave a widened hole and thus introduce inaccuracies in the drawing.

In accordance with the present invention there is promided a drawing instrument with a plurality of spaced holes for insertion of a pencil for drawing curved and straight lines at selected spaced locations and with a portion adjacent a central hole for mounting a pricking pin in a new and unusual manner. In accordance with a pre ferred arrangement of the invention, the pricking pin is held centrally within a cylindrical block which is embraced by a curved spring clip or mounting element over an arc of more than 180. The spring clip advantageously includes arm portions extending outwardly from the curved portion surrounding the cylindrical block which are formed as upward extensions of coil spring portions formed on each side of the block. The spring clip includes a central axle portion between the coil spring portions which is rotatable within a bearing bore formed on the instrument. In profile the spring has a substantially S-shaped configuration, the lower portion of the S being formed adjacent the pivotal connecting portion, and with the upper portion extending substantially parallel to the lower portion and forming the holding part for the cylindrical block containing the pricking pin.

A feature of the present invention is that the cylindrical block is held in a position such that the pin projecting downwardly from the block will be supported within a central opening defined in the instrument but without projecting therethrough. The characteristic of the spring mount is that when the projecting arms are depressed, the pin will be moved substantially parallel to the axis of the opening and into the paper or other sheet material which underlies the instrument.

Accordingly, it is an object of the invention to provide an improved instrument construction having holes of unique formation and location for receiving an inscribing instrument and having means for mounting a pricking tip in a non-operative position and for permitting the tip to be moved through an opening defined in the instrument.

A further object of the invention is to provide a drawing instrument having a pricking tip which is maintained out of operative position so that the tip will not project in an unsafe manner with means resiliently mounting the pricking tip so that it may be moved substantially parallel to an opening defined in the instrument for insertion into a material disposed beneath the instrument.

A further object of the invention is to provide a novel mounting for a pricking tip of a device such as a drawing instrument having a plurality of openings for receiving a stylus, and including a central opening for locating a center which includes a spring member formed of one piece and including a lower central bearing portion with coil spring portions on each end, and with an upper portion angled upwardly from each coil spring portion which extends around a substantial portion of a block member holding a pricking pin, the upper portion being oriented so that the block portion moves substantially parallel when the spring is depressed.

A further object of the invention is toprovide a drawing instrument that is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize'the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a etter understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a top plan view of a drawing instrument constructed in accordance with the invention;

FIG. 2 is a partial sectional view taken on the line IIII of FIG. 1;

FIG. 3 is an enlarged top plan view of the portion of the instrument indicated in FIG. 2; and

FIG. 4 is a side elevational view of the mounting spring for the pricking tip.

Referring to the drawings in particular, the invention embodied therein comprises a generally trapezoidalshaped drawing instrument such as a flat plate element generally designated 2 having a top or narrow side 3, oblique sides 4 and 5, and a bottom or long side 6. In the embodiment illustrated, the sides 4 and 5 make an angle of 60 in respect to the long side 6.

On the long side 6, in the center thereof, there is provided a projection or prolongation 7 having a raised portion or mounting block 8 with a central high portion having bore 9 defined thereth-rough which forms a bearing opening for rotatably supporting mounting means such as a mounting spring generally designated 22. The drawing instrument 2 is formed to provide a protractor having angular graduations l0 and linear graduations or measuring marks indicated as arcs of a circle 11. Scales designated 12 are provided for association with the measuring marks 11. The measuring marks present number scales l2 offset in relation to each other by each occurrence, which facilitates the location of a desired radius.

The common center of all the measuring marks 11 is an opening or hole 14. Each measuring mark 11 presents at least two holes 15 and 15a which are offset in relation to each other by 90 and which, on the side toward the user of the instrument, are in the form of a truncated cone, and on the side away from the user are cylindrical (see FIG. 2). The holes and 15a differ only in their diameters, which are selected to permit satisfactorily the use of ballpoint pens and tube pens, as well as sharply pointed pencils for employing the drawing instrument. By employing holes which are offset in relation to each other by 90 and arranged in zig-zag form, a maximum of clarity at a minimum of space requirement is achieved in respect to the scales of the instrument which facilitates work with the instrument.

In accordance with the invention, a pricking tip or pointed element 16 is carried centrally within a cylindrical head or block element 20 having a recess 21 formed as a guide cone for the pricking pin 16. A feature of the construction is that the block 20 is supported by the mounting means 22 which comprises a one-piece helical spring which is of substantially S-shaped configuration in side elevation, as indicated in FIG. 4. The spring mounting means 22 includes a central hearing or pivoting portion 26 which is positioned in the bore 9 and rotatable therein. The opposite ends of the central portion 26 are connected to coil spring portions 24 and 23, respectively, which rest on flat base portions on each side of the raised central portion 8a of the block 8. Side leg portions 22a, 22a extend outwardly and then upwardly obliquely from the respective spring portions 23 and 24 and at their upper ends are formed into curved handle or finger-engaging portions 25. The finger-engaging portions 25 extend backwardly and are formed, or lead into, a central cylindrical loop portion 27 which fits into a recess 28 formed on a side of the block 20 and tightly embraces and holds the block 20 in an elevated position. It is preferable that the curved portion 27 extend around the block by at least 180. The upper ends of the legs 25 and the central curved portion 27 are disposed in substantially the same plane as the convolutions of the spring portions 23 and 24 in order to hold the pricking tip 16 vertical. By such an arrangement and design, the spring mount-ing means 22 insures that the pricking tip 16 can be guided from the non-operative ready position indicated in solid lines in FIG. 2 either to an upward position removed from the instrument, as indicated in dotted lines in FIG. 2, or to a downward operative position in which the pricking tip 16 is engaged in an underlying element, such as a sheet of paper upon which the drawing lines are to be made. When the mounting means 22 is moved to a position indicated in dotted lines in FIG. 2, the spring elements 23 and 24 will bear against the side portions of the block 8 in the manner of a stop and prevent further pivoting of the mounting means and the pin 16. The device may be moved beyond this position by the exertion of additional pressure to overcome the stopping action on the ends of the springs 23 and 24.

The drawing instrument 2 advantageously comprises a transparent material, preferably a scratch-resistant plastic, in which the measuring marks are etched, printed, or embossed in a conventional manner. The pricking tip or pin 16, with its head, is made of steel.

When working with the drawing instrument described, after it is located in respect to the drawing sheet, the pricking tip 16 may be positioned as desired by merely pushing downwardly on the finger-engaging portions 25. In this manner the pin will move substantially parallel to the axis of the opening 14. A writing instrument is introduced in one of the holes 15, 15a, and by moving the instrument, the required arc may be drawn or the desired radius marked. If desired, the instrument may also be employed using the straight edges to draw lines. To detach the pricking tip from its support, it is only necessary to apply an upward lifting pressure at the finger-engaging portion 25. Upward pressure sufiices to move the pricking tip 16 into the ready position indicated in FIG. 2, and the drawing instrument may be shifted, as necessary.

The pricking tip 15 is again in position for immediate use once the instrument is re-located.

The instrument described may be employed as a protractor, a circle templet, or as a device for drawing: polar coordinates, circles, straight lines enclosing a certain angle, parallel lines such as hatchings, etc., without the use of additional aids such as a compass or the like.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. A drawing instrument comprising a flat plate element having a plurality of spaced holes therethrough for receiving the point of a writing instrument and for receiving a centering pricking tip, a pricking tip element, a bearing block portion defined on said flat plate element, and means mounting said pricking tip element on said flat element adjacent one of said holes normally holding said pricking tip element on said fiat element adjacent one of said holes normally holding said pricking tip element substantially normal to said flat element and within one of the holes but not projecting outwardly therefrom, said mounting means being movable to move said pricking tip element substantially normal to said fiat plate element and through the associated hole to project outwardly through the opposite side of said plate element for engaging into a material to be inscribed, said mounting means comprising a resilient spring member, said spring member having a central portion which is rotatable in said bearing block portion, said spring member including coiled portions on each side of the central portion of said spring member, side portions extending outwardly and upwardly from each of said coiled portions and being looped at the outer ends to form finger-engaging portions, and a coiled central portion forming a pricking tip element supporting portion formed between said finger-engaging portions.

2. A drawing instrument comprising a fiat plate element having a plurality of spaced holes therethrough for receiving the point of a writing instrument and for receiving a centering pricking tip, a pricking tip element, and means mounting said pricking tip element on said fiat element adjacent one of said holes normally holding said pricking tip element substantially normal to said fiat element and within one of the holes but not projecting outwardly therefrom, said mounting means being movable to move said pricking tip element substantially normal to said flat plate element and through the associated hole to project outwardly through the opposite side of said plate element for engaging into a material to be inscribed, said mounting means comprising a resilient spring member, said instrument having a bearing block portion, said spring member having a central portion which is rotatable in said bearing block portion, said spring member including coiled portions on each side of said central portion, side portions extending outwardly from each of said coiled portions and being looped at the outer ends to form finger-engaging portions and curved centrally between the finger-engaging portions to form a pricking tip element supporting portion, a pricking tip element mounting block having a groove defined along its peripheral edge, said curved portion of said mounting means embracing said mounting block and holding said mounting block substantially parallel to the face of said fiat element, said block having a central opening defined therethrough substantially perpendicular to said flat element for receiving said pricking tip element.

3. A drawing instrument comprising a flat plate element having a plurality of spaced holes therethrough for receiving a centering pricking tip, a pricking tip element, and means mounting said pricking tip element on said flat element adjacent one of said holes normally holding said pricking tip element substantially normal to said fiat element and within one of the holes but not projecting outwardly therefrom, said mounting means being movable to said pricking tip element substantially normal to said flat plate element and through the associated hole to project outwardly through the opposite side of said plate element for engaging into a material to be inscribed, said flat plate element having a projection formed on one side thereof adjacent one of said holes, the hole adjacent the projection being located centrally in respect to the associated edge of said flat plate element, a raised block portion on said projecting element having a central portion with a bearing bore defined therethrough, said mounting means including a spring element having a central portion which is rotatable in the bore of said block portion.

4. A drawing instrument comprising a flat plate element having a plurality of spaced holes therethrough for receiv ing the point of a writing instrument and for receiving a centering pricking tip, a pricking tip element, and means mounting said pricking tip element on said flat element adjacent one of said holes normally holding said pricking tip element substantially normal to said flat element and within one of the holes but not projecting outwardly therefrom, said mounting means being movable to move said pricking tip element substantially normal to said flat plate element and through the associated hole to project outwardly through the opposite side of said plate element for engaging into a material to be inscribed, said flat plate element having a projection formed on one side thereof adjacent one of said holes, the hole adjacent the projection being located centrally in respect to the associated edge of said flat plate element, a raised block portion on said projecting element having a central portion with a bearing bore with the central portion being raised from said flat plate element to a greater extent than the side portions thereof, said mounting means including a spring element having a central portion which is rotatable in the bore of said block portion, and coil spring formations at each end of said central portion which rest on the respective side portions of said block.

5. A drawing instrument comprising a flat plate element having a plurality of spaced holes therethrough for receiving the point of a writing instrument and for receiving a centering pricking tip, a pricking tip element, and means mounting said pricking tip element on said flat element adjacent one of said holes normally holding said pricking tip element substantially normal to said flat element and within one of the holes but not projecting outwardly therefrom, said mounting means being movable to move said pricking tip element substantially normal to said flat plate element and through the associated hole to project outwardly through the opposite side of said plate element for engaging into a material to be inscribed, said flat plate element having a projection formed on one side thereof adjacent one of said holes, the hole adjacent the projection being located centrally in respect to the associated edge of said flat plate element, a raised block portion on said projecting element having a central portion with a bearing opening, said mounting means including a spring element having a central portion which is rotatable in the bore of said block portion, said block portion having portions on each side which do not project upwardly from the flat plate element as much as the central portion, said mounting means including coil spring formations at each end of said central rotatable portion which rest on the respective side portions of said block,

said mounting means including side portions extending horizontally outwardly from the top of said coil spring portions and then obliquely upwardly, handle portions formed as substantially horizontal loops connecting said side portions and bent inwardly, and a curved central portion connecting said handle portions, said curved central portion forming a support for said pricking tip element.

6. A device for use in association with a drawing instrument and the like comprising a mounting block having a bore therein, a one-piece spring element including a central portion extending through the bore of said mounting block, coil spring portions on each side of said central portion having coil axes which are substantially perpendicular to the axis of said central portion, side portions connected to the tops of each of said coil spring porengaging portions defined at the upper ends of said side portions and extending inwardly therefrom in the form of loops, and a central curved portion formed between said finger-engaging portions, a pricking tip holding block held by said central portion, a pricking tip element held by said block and projecting downwardly therefrom, said fingerengaging portions being depressable to move said block with said pricking tip element in directions substantially parallel to the axis of said pricking tip element.

7. A device for use in association with a drawing instrument and the like comprising a mounting block having a bore therein, a one-piece spring element including a central portion extending through the bore of said mounting block, coil spring portions on each side of said central portion having axes which are substantially perpendicular to the axis of said central portion, side portions connected to the tops of each of said coil spring portions and extending obliquely upwardly therefrom, finger'engaging portions defined at the upper ends of said side portions and extending inwardly therefrom in the form of loops, and a central curved portion formed between said finger-engaging portions, a pricking tip holding block held by said central portion, a pricking tip element held by said block and projecting downwardly therefrom, said finger-engaging portions being depressable to move said block with said pricking tip element in directions substantially parallel to the axis of said pricking tip element, said block having a raised central portion having said bore therein with side portions of reduced dimension, said coil spring portions of said spring mounting means resting in the side portions of said mounting block to hold said pricking tip element block in a position in which the pricking tip element is non-operative.

References Cited by the Examiner UNITED STATES PATENTS 1,139,229 5/1915 Requa 33-104 1,995,204 3/1935 Ford 33104 2,003,172 5/1935 Burt 33-1 2,768,443 10/ 1956 Chiaravalloti 3327 FOREIGN PATENTS 342,114 1/ 1931 Great Britain. 163,381 5/1958 Sweden.

LEONARD FORMAN, Primary Examiner.. ISAAC LISANN, Examiner. HARRY N. HAR'OIAN, Assistant Examiner. 

1. A DRAWING INSTRUMENT COMPRISING A FLAT PLATE ELEMENT HAVING A PLURALITY OF SPACED HOLES THERETHROUGH FOR RECEIVING THE POINT OF A WRITING INSTRUMENT AND FOR RECEIVING A CENTERING PRICKING TIP, A PICKING TIP ELEMENT, A BEARING BLOCK PORTION DEFINED ON SAID FLAT PLATE ELEMENT, AND MEANS MOUNTING SDAID PRICKING TIP ELEMENT ON SAID FLAT ELEMENT ADJACENT ONE OF SAID HOLES NORMALLY HOLDING SAID PICKING TIP ELEMENT ON SAID FLAT ELEMENT ADJACENT ONE OF SAID HOLES NORMALLY HOLDING SAID PICKING TIP ELEMENT SUBSTANTIALLY NORMAL TO SAID FLAT ELEMENT AND WITH ONE OF THE HOLES BUT NOT PROJECTING OUTWARDLY THEREFROM, SAID MOUNTING MEANS BEING MOVABLE TO MOVE SAID PICKING TIP ELEMENT SUBSTANTIALLY NORMAL TO SAID FLAT PLATE ELEMENT AND THROUGH THE ASSOCIATED HOLE TO PROJECT OUTWARDLY THROUGH THE OPPOSITE SIDE OF SAID PLATE ELEMENT FOR ENGAGING INTO A MATERIAL TO BE INSCRIBED, SAID MOUNTING MEANS COMPRISING A RESILIENT SPRING MEMBER, SAID SPRING MEMBER HAVING A CENTRAL PORTION WHICH IS ROTATABLE IN SAID BEARING BLOCK PORTION, SAID SPRING MEMBER INCLUDING COILED PORTIONS ON EACH SIDE OF THE CENTRAL PORTION OF SAID SPRING MEMBER, SAID PORTIONS EXTENDING OUTWARDLY AND UPWARDLY FROM EACH OF SAID COILED PORTIONS AND BEING LOOPED AT THE OUTER ENDS TO FORM FINGER-ENGAGING PORTIONS, AND A COILED CENTRAL PORTION FORMING A PICKING TIP ELEMENT SUPPORTING PORTION FORMED BETWEEN SAID FINGER-ENGAGING PORTIONS. 